The present invention relates to the field of portable radiotelephones, and more particularly, for inputting data into such devices.
Current portable radiotelephones provide a host of features in addition to that of making and receiving telephone calls. Such additional features include the storing and retrieving of telephone numbers and names from an internal phone book, to the sending of textual messages to other users.
Current portable radiotelephones generally comprise at a least a numeric keypad, for composing telephone numbers, and a number of additional function keys, for initiating communications to a desired telephone number, turning the radiotelephone on and off etc. It is also common for the numeric keypad to also contain alphabetic representations, for allowing the construction of textual messages. Typically, each numeric key represents three alphabetic characters, for example, the numeric key ‘2’ often also represents characters ‘A’, ‘B’ and ‘C’. During the construction of a textual message, each press of a numeric key causes a display to cycle through each character represented by that key. For example, a first press of numeric key ‘2’ would cause the character ‘A’ to be displayed, a second press would cause the character ‘B’ to be displayed and so on. When the desired character is displayed, a further character may be entered either after a short delay, or by pressing another key. In this way textual messages may be constructed. A textual message may then be transmitted to another user in a variety of ways which will be apparent to those skilled in the art.
One problem with the above method is that the construction of textual messages is somewhat arduous since each key may require multiple presses in order to select the required character.
In order to overcome this problem, some radiotelephones now comprise typewriter style keyboards. Whilst allowing the easier entry of text, such keyboards are large and cumbersome. Radiotelephones incorporating such keyboards are thus also large. Reducing the size of such a keyboard, however, makes it increasingly difficult to select the required key, since the keys of the keyboard become smaller than the size of a finger tip, and results in an increased chance of the wrong key being pressed.
Accordingly, one aim of the present invention is to provide improved data input means for use with a portable radiotelephone.